Diagnosing roaming issues (with iOS)

Hello -

I have a site with 10 APs in a dense urban location. I was able to have an onsite person do a good survey with an Ekahau Sidekick. There is massive 2.4 interference as suspected. However we were able to get a good 5Ghz channel mapping scheme so there is little to no interference.

So after setting up a dedicated 5G SSID, we ran through our key use case which is a Facetime call on an iPhone walking through the location at a fast walk.

We confirmed we have excellent primary signal strength and secondary signal strength with the survey, as well as clean channels.

I was feeling confident once we got to a dedicated 5G SSID that things would be better. It turns out that despite our dedicated 5G SSID, the subjective performance is better on the 5G and 2.4G SSID.

We had some mixed capability APs - some Ruckus R610 along 3 newer R550. Once we turned off 802.11ax - that helped our 5G only SSID, but still was not performing well enough (roams were very rough).

802.11k and r are turned on.

Upon further digging, I see iOS devices stubbornly hang on until -71 db. There are some very poorly placed placed APs but we do have sufficient total number of units to support signal strength.

My challenge now is to try to pin down what is preventing the iOS / mobile device from not roaming well. Watching Joel Crane demo on Tonic I saw a hint that maybe there was going to be a device follow feature on Tonic. I’m completely new to the tool. I’m hoping for anyone to give me some advice on how to nail down what the roaming issue could be.

Generally, clients not moving will associate to the appropriate AP and will work well when not in motion.

I was hoping I could pin the problem on the huge amount of 2.4 interference but with dedicated 5G SSID that seems to offer WORSE performance, something else is going on.

Any tips, tricks or hints massively appreciated. Anyone have feedback implementing Sapphire Eye from 7signal?


5G Signal Strength


2.4 Interference - Blue are our APs red are neighbor APs

First you need to realize that Apple products have pitifully low WIFI output power. We were testing iPads for locationing and found 18mw output max. This impacts you in the bidirectional communications if you have any obstructions in the facility. You also should look at the output power on the AP’s, you can’t have them set at much higher power than the client they are communicating to, this will make the client “appear” sticky to the AP’s, but in reality, the AP range exceeds the client range. Balancing power could force you to add more AP’s to provide complete coverage. But if the iPhones are the main client you may have no alternative. Also the higher frequency of 5.8, any obstructions can create shadow areas that can change with the environment. Closed doors, stacked boxes or even people… Your heat map shows fairly good coverage but I have no reference point as to the dbm level in the map. Is the yellow -71dbm? In those areas the iPhone has no better AP signal to link to…